The present invention relates to an electronic equipment cooling structure capable of satisfactorily cooling electronic printed circuit boards to be mounted in a frame of electronic equipment. More particularly, the present invention relates to an improved jet cooling apparatus for cooling electronic equipment that is satisfactorily adaptable to local cooling, and to a computer on which the jet cooling apparatus is mounted.
Hitherto, cooling of electronic equipment has been, as disclosed in, for example, Japanese Patent Laid-Open (i.e. Unexamined Publication) No. 61-85899, performed by using cooling fans disposed in a frame accommodating a multiplicity of electronic printed circuit bards, which are heat generating members, at longitudinal or vertical positions with respect to the electronic device groups to collectively cool all of the electronic printed circuit boards accommodated in the frame by the fans.
As is known in, for example, Japanese Patent Laid-Open No. 64-28896, if devices, the heating values of which are different, are mixed, use of individual concentrated air cooling means, separately from common air cooling means having the foregoing cooling fan, has been also considered.
An example of this has been disclosed in U.S. Pat. No. 4,851,965 (Jul. 25, 1989). In this case, a duct so disposed in parallel to the printed circuit boards as to cool IC chip groups mounted on printed circuit boards to be cooled has circular apertures. Furthermore, the diameters of the apertures are varied depending upon the heating values of the chips. As disclosed in Japanese Patent Laid-Open No. 1-115198, a duct, the cross sectional area of which is reduced downstream in the direction of the flow, is disposed above the top surfaces of the heat generating printed circuit boards, cooling air jetting ports are formed in the portions of the duct that correspond to the heat generating devices, and the jetting ports are closed by thermally deformable films.
However, the above-mentioned conventional cooling apparatus, in particular, the apparatus adapted to the total and collective cooling system disclosed in Japanese Patent Laid-Open No. 61-85899 encounters a problem in that a portion of the cooling air is not effectively used and accordingly the cooling efficiency is unsatisfactory. If a device which generates heat of a large heating value is locally present, the foregoing example must increase the overall air quantity to be supplied to the frame. In this case, the cooling air must be supplied by an extraordinary large quantity, causing a problem to take place in that noise of the cooling fan and/or the duct cannot be ignored.
The example disclosed in Japanese Patent Laid-Open No. 64-28896 suffers from a disadvantage that the duct and the air passage which constitute the concentrated air cooling means become too large and complicated. Therefore, the disclosed example is not suitable to simultaneously and concentratedly cool a plurality of the electronic printed circuit boards.
The example disclosed in U.S. Pat. No. 4,851,965 has a problem that the cost cannot be reduced because the small apertures are formed by the number of the chips. Another problem arises in that the small aperture can be clogged with dust or the like contained in the cooling air. Moreover, another problem of the pressure loss takes place because a throttle is provided in the passage for the cooling air.
In the case of Japanese Patent Laid-Open No. 1-115198, if the thermally deformable films are once melted by the heat of the heat generating devices, the jetting ports are brought to a state as if they were opened at the initial moment. Therefore, the structure becomes too complicated, and no means has been employed to prevent the pressure loss of the cooling air.